1. Field of the Invention
The present invention relates to the field of displays, and more particularly, to a metal oxide thin-film transistor (TFT), a method of fabricating the metal oxide TFT, and an array substrate.
2. Description of the Prior Art
Copper features excellent electric conductivity so it is usually used as an electrode when a metal oxide TFT is produced. Copper, with certain diffusivity, is inclined to be spread to a metal oxide active layer when a TFT is conducted, which may affect the electric conductivity of the metal oxide active layer. Therefore, instead of using copper alone, multiple layers are used in the conventional technology, including a blocking spread layer and a copper layer. The blocking layer is usually formed by molybdenum (Mo) or titanium (Ti) to prevent copper from spreading to the metal oxide active layer.
However, the conventional technology has two shortcomings. One is that, it is impossible to fabricate a blocking spread layer with a larger thickness by a manufacturer because of the costs and the thickness of devices have to been controlled strictly though the fact is that the thicker the blocking spread layer is, the better effect of preventing copper from spreading to the metal oxide active layer is. The other is that, annealing is conducted on the fabricated TFT for improving the performance of the device. However, annealing has to be conducted in the environment of high temperature. It means that copper also spreads rapidly in the environment of high temperature. Because the blocking spread layer is poor in preventing copper from spreading, both of the electric conductivity of the metal oxide active layer and the performance of the TFT are negative affected.
Therefore, it is necessary to improve the faulty conventional technology.